The morning news. [volume] (Savannah, Ga.) 1887-1900, 1887-09-27
HOW THE LAMPS ARE MADE.
Some Things About the Incandescent
Light-The Carbon Threads

Since the introduction of the incandeS
cent system of electric lighting in Savan
nah there has been great deal of inquiry
about the mechanism of the lamp, what il
is and how it is made. The light emitted
| from the lamp is from thread of carbon
| heated by the electric current until 1t glowS
| with an almost white heat.
A MORNING NEWS reporter visited the
Brush Companyis works on Indian street
last night, and watched the generation OF
the current which lights the thousand lamps
all over the city The little thread of car
bon, which many call a wire, inside the
glass globes, is made from some animal or
vegetable substance, such as cotton or linen
thread, silk. bamboo, hair, and sometimes
of celluloid The thread is baked in an
oven, excluded from the air until
all volatile matter is excluded, and nothing
remains but a shiny black thread of char
coal or carbon. If the thread were heated
and exposed to the air it would burn up in
stantly. In order to fit it for a durable
lamp it is placed in glass bulb and the air
pumped out; il is then sealed up hermetl-
cally. In this state it can be used for a long
time without being consumed. The average
life of the lamps used in Savannah is 800
hours
The difference in lamps is very little, ex-
cept in the preparation of the carbon thread
on 'flament," as il is called.
THE "FILAMENTn
Every maker claims something superior
for his own lamps. The length of the fila
ment and its thickness is in proportion TO
the pressure and quantity of electricity
which it is designed to carry, and also the
candle power. II the current is to be of
high pressure the thread of carbon is made
longer, or, if the current pressure is lower
~ a Il A
rent of large quantity" possesses greater
economy, in heating effects, than one of
higher pressure and less quantity. But high
pressure is necessary to overcome the resis-
lance to the flow of the current over the
wires or conductors The majority of the
different systems of electric incandescent
lighting use direct current from their dy-
namoS TO the lamps.
THE WESTINGHOUSE SYSTEM.
In the Westinghouse system, which is the
one adopted by the Brush Company, of
this city, the current is alternating, that
is, it is reversed in its direction very rap
idly. A high pressure and small quantity
current from the dynamo to the lines is
used in order to use smaller wires for con-
ductors. At convenient points, for the SER
vice of lamps, they place upon their poles
induction coils or "converters," as they are
called The Office of the converter is pecu-
liar The line current passes through one
coil of wire in the converter, and near that
coil, but not connected with it in any way,
is another coil of wire in which is generated
a current by induction The induced cur
rent is of low pressure and of large quanti-
ty, just suited for the short distance and
low resistance between the converter and
the lamps. The current to the convert
ers is called the primary" and the one
from the converter to the lamps is called
secondary" The latter current is not ca
pabe of giving any electric shock, as it is
scarcely perceptible
20 DANGER OF LIGHTNING.
There is no danger of lightning ever
entering building for the conductors ex-
tend only short distance to the converters.
The incandescent light is steady, bright,
and emits very little heat. 1t consumes no
oxygen, Therefore it is the most whole
some light in the world. When the wires
are properly put into building, they have
inserted into them, at the entrance and the
several branches, strips of lead or fusible
composition, which will melt out or cut off
the flow of currents. The leads are called
FUSES and are so proportioned for the
size OF wire and current, that they will melt
out before the wires are hot enough to
ignite anything. There is, therefore, no
danger of fire originating from the
wires of a current if the work is properly
done.